Americans 12 and older can get a Covid-19 vaccine, but younger children are still waiting. With many schools across the United States are now just weeks from reopening for the fall semester, pharmaceutical companies Pfizer and Moderna are still doing clinical trials to see how coronavirus vaccines work in children under 12, if they're safe and what the right dose should be. Meanwhile, all but four states are seeing an increasing trend in cases, with doctors describing patients who are younger and sicker than what they saw in the winter. The surge in cases has many parents of children under 12 asking when will their little and not-so-little ones can get the vaccine. The answer is that it's going to be months, if not longer. It's not as simple as administering available adult doses to younger people.